1. Field of the Invention
Embodiments of the present disclosure relate to a non-aqueous electrolyte secondary battery provided with a wound electrode body.
2. Description of the Related Art
Non-aqueous electrolyte secondary batteries such as lithium secondary batteries are lighter and have higher energy densities than existing batteries, and have therefore been used in the past in so-called portable power sources for personal computers, hand-held devices and the like, in power sources for propelling vehicles, and in residential power storage devices and the like. In particular, non-aqueous electrolyte secondary batteries have been advantageously used in recent years as high output power sources for propelling vehicles such as electric vehicles (EV), hybrid vehicles (HV) and plug in hybrid vehicles (PHV), which have high capacities and are subjected to high rate discharging.
In this type of non-aqueous electrolyte secondary battery, a positive electrode provided with a positive electrode active material layer and a negative electrode provided with a negative electrode active material layer are disposed so as to face each other, with a separator interposed therebetween, and are housed in a battery case together with a non-aqueous electrolyte solution. In general, the non-aqueous electrolyte solution is impregnated in the positive electrode active material layer, negative electrode active material layer and separator. In addition, charging and discharging can be carried out by causing electrolyte ions to move between the positive and negative active material layers and the positive and negative active materials storing and releasing electrolyte ions. Here, proposals have been made regarding features and materials of separators in order to impart separators with high mechanical strength, high electrolyte retention properties and ion conductivity (for example, see Japanese Patent Application Publication No. 2006-092829 and Japanese Patent Application Publication No 2010-500717, etc.).